The present invention relates to a multi-band microwave oscillator.
A general difficulty in adapting microwave techniques for consumer and commercial applications is the difficulty of fabricating cheap structures which are not confined to a relatively narrow bandwidth. For example, satellite down links and assigned satellite broadcast bands are widely spaced across the microwave spectrum, and it is difficult enough to design a receiver to cover much of any one band, without attempting to cover multiple bands. However, the ability to select among channels of reception is highly desirable, not only to permit user versatility, but also to allow for adaptation to changing weather conditions, which may affect the propagation characteristics of different frequency bands differently. Multi-band capability in a local oscillator permits multi-band reception in a conventional superheterodyne receiver, but there is at present no cheap way to achieve such multi-frequency capability in a single microwave local oscillator.
Frequency-agility is useful in frequency-hopping communications systems. Such systems have been proposed to obtain better spectrum utilization where many users each have a low individual use rate and independent access as with mobile radio networks. Frequency-hopping agility is also useful in many military applications, particularly electronic countermeasures.
It is thus an object of the present invention to provide a multi-band microwave oscillator.
It is a further object of the present invention to provide a multi-band microwave oscillator which can be very economically fabricated.
It is a further object of the present invention to provide a very cheap multi-band microwave communications receiver.